1. Field of the Invention
This invention relates to the field of chemical engineering and to solute-solvent separation and more particularly, to apparatus and method suitable for consumer and industrial use in distilling of water.
2. Description of the Prior Art
Techniques for the separation of a solute from a relatively non-volatile solvent are well known and have been used for a number of years. However, such techniques are often complex in operation, inexpensive and consume large amounts of energy. Thus, the application of these techniques, on a large scale, is limited. For example, the purification of water from a saline source or brackish supply or from tap water, requires a considerable amount of structure. Various approaches for water purification from sources of the type described include multi-stage flash evaporation making use of reduced pressure for evaporation; reverse osmosis using hydrostatic pressures; vacuum freezing; distillation (mostly batch type) based on the boiling of water; moisture recovery based on large amounts of air-water contact; and electrodialysis based upon ion exchanges.
The problems which the foregoing approaches encounter are significant, such as the fabrication of special membranes, and the use of special alloys for protecting machinery against corrosion or scaling. Many of these techniques also require high energy consumption for mechanical or evaporation purposes. Similar considerations are often involved in the purification concentration and separation techniques for solution of relatively non-volatile solvents or solutes.
It is especially desirable to have available at a point of use, purified water both for drinking and other purposes. Firstly, the health benefits are well known; secondly, a centralized purified water supply could not maintain its high quality if it is delivered through conventional plumbing structures; thirdly, while there are water purification devices which are commercially available, they are not modestly priced, and they require frequent maintenance or replacement of key components while consuming large amounts of energy during operation.
Because of the numerous problems associated with conventional structures mentioned above, it is advantageous for household and public use to be able to conveniently and economically purify water from water supplies at the point of use of the water. The present invention relates in particular to improvements in distillation apparatus and methods which will satisfy the need for such a water source.